1. Field of the Invention
The present invention relates to a cleaning device and an image-forming device.
2. Description of the Related Art
Conventionally, there is known a cleaning device with a rotational brush and a solid lubricant. Furthermore, there exists an image-forming device with the cleaning device. The rotational brush touches a fixed lubricant, and scrapes the surface of the lubricant by rotating. The brush is arranged so as to touch an image holder, thereby applying the scraped lubricant onto the surface of the image holder.
For example, the following advantages are obtained by applying a lubricant on the surface of an image holder:
because of the applied lubricant, a toner image formed on the surface of the image holder separates easily from the surface thereof, and transferability of the toner image is improved;
abrasion of a remover (for example, a blade) which touches the surface of the image holder and removes residues on the surface thereof is suppressed by the lubricant, and removal performance of the remover is kept; and
abrasion of the surface of the image holder caused by being touched by the brush and the blade is suppressed by the lubricant, and a sufficient life period of the image holder is ensured.
When a lubricant is applied non-uniformly on the surface of an image holder, a streak may be generated on an image formed on paper. For example, when a brush has straight bristles, the bristles may hold much toner remaining on the surface of an image holder. When the bristles hold much toner, the bristles can hold little lubricant. When the bristles hold little lubricant, the brush cannot apply the sufficient amount of lubricant on the surface of the image holder. As a result, the lubricant is applied non-uniformly onto the surface of the image holder.
FIG. 11 shows a cross-section diagram of a lubricant which is applied on the surface of an image holder uniformly, sectioned in the direction of a rotational axis of an image holder.
FIG. 12 shows a cross-section diagram of a lubricant which is applied on the surface of the image holder non-uniformly, sectioned in the direction of the rotational axis of the image holder.
As shown in FIG. 11, when a lubricant is applied uniformly in the direction of the rotational axis of the image holder, a streak is not generated on an image formed on paper. On the other hand, as shown in FIG. 12, when a lubricant is applied non-uniformly in the direction of the rotational axis of the image holder, a streak is generated on an image formed on paper.
For example, the following arts can apply a lubricant uniformly.
Japanese Patent Application Laid-open Publication No. 2009-109573 discloses a uniformizing member which is arranged behind a brush in the rotational direction of an image holder, wherein the uniformizing member uniformizes the lubricant applied by the brush on the surface of the image holder.
Japanese Patent Application Laid-open Publication No. Heisei 10-26916 discloses that looped bristles can hold more lubricant than toner remaining on the surface of an image holder, and that the size of bristles is defined and the bristles contact the surface of the image holder uniformly so that the lubricant can be applied thereto uniformly.
However, when a uniformizing member is arranged in a cleaning device, the cleaning device becomes large.
Furthermore, when looped bristles are used for a brush, scraping power of the brush increases, and the brush scrapes the lubricant applied on the surface of the image holder beforehand with the bristles thereof. As a result, the lubricant may not be uniformly applied on the surface of the image holder. That is to say, a lubricant cannot be applied uniformly on the surface of an image holder by only defining the size of bristles of a brush.